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ETALDOC 591/8

Page 1 of 5

January 2001

PRODUCT DATA SHEET

LOW COST, LOW DISTORTION

P3356

LINE MATCHING TRANSFORMER

Features

Applications

∗

Low Cost

∗

V.90 and V.92 Modems

∗

Low Distortion

∗

V.34 Modems

∗

12.6mm (0.5”) Seated Height

∗

Fax Machines

∗

Industry Standard Pinout

∗

Instrumentation

∗

IEC 950, UL 1950 and EN 60950 Certified

∗

UL Recognized Component

∗

BABT Certificate of Recognition

∗

Extended Frequency Response

∗

Flat TX and RX Responses

∗

Simple Matching

∗

Low Insertion Loss

∗

High Thermal Stability

DESCRIPTION

P3356 is intended for V.90 and V.92 (56kbps)
modems and other high-speed applications where
ultra-low distortion at moderate power levels and
very low voiceband frequencies is required at a
most competitive price.

P3356 uses patented design and construction
methods to achieve excellent signal performance
and safety isolation to international standards at
truly low cost, making it the component of choice
for high-speed data applications throughout the
world. P3356 is certified to IEC 950,
EN 60950, EN 41003, and CAN/CSA C22.2
No. 950-95/UL1950. P3356 is a UL Recognized
Component, and is supported by a BABT
Certificate of Recognition and an IEC CB Test
Certificate.

P3356 has exceptionally flat frequency response
from 30Hz to 10kHz, a 3dB bandwidth of over
50kHz and requires only the very simplest of
matching to achieve good return loss and
transhybrid loss across the voiceband, with very
low levels of signal distortion at signal
frequencies as low as 150Hz.

P3356 also exhibits stable characteristics over its
full operating temperature range to maximize
data throughput under varying environmental
conditions without the need for modem
retraining.

Patented

E203175

to Electronic Techniques

(Anglia) Limited

P3356

ETALDOC 591/8

Page 2 of 5

January 2001

SPECIFICATIONS

Electrical

At T = 25ºC and as circuit Fig. 2 unless otherwise stated.

Parameter

Conditions

Min

Typ

Max

Units

Insertion Loss

f = 2kHz, R

= 600

Ω

1.5

Frequency Response

LF -3dB cutoff
HF -3dB cutoff
100Hz – 4kHz

-
-
-

10
55

-
-

0.1

kHz

Return Loss

(5)

200Hz – 4kHz

Transhybrid Loss

(5)

200Hz – 4kHz

Third Harmonic
Distortion

(1)

150Hz -3dBm in line
200Hz -10dBm in line

-
-

-70
-89

-
-

dBm
dBm

Voltage Isolation

(2)

50Hz
DC

2.12

3.0

-
-

kVrms

Operating Range:
Functional
Storage

-40

-
-

+70
+85

ºC
ºC

Lumped equivalent circuit parameters as Fig. 1

DC resistance

(3)

Primary resistance R

DCp

Secondary resistance R

DCs

70
95

-
-

120

Ω

Leakage inductance,

∆

3.9

Shunt inductance, Lp

(4)

200Hz -43dBm

Shunt loss, Rp

200Hz -43dBm

Ω

Notes:

1. Third harmonic typically exceeds other

harmonics by 10dB.

2. Components are 100% tested at 3.25kVDC.
3. Caution: do not pass DC through windings.

Telephone line current must be diverted using
semiconductor line hold circuit or choke.

4. At signal levels greater than –20dBm, Lp will

increase and Rp will decrease slightly but the
effect is usually favourable to the return loss
characteristic.

5. Return loss and transhybrid loss can be

improved to 30dB in improved matching circuit.
The values shown relate to the simplest
configuration, Fig. 2.

Equivalent Circuit

Fig. 1

IDEAL

1:1

½ L

P3356

ETALDOC 591/8

Page 3 of 5

January 2001

MATCHING RECOMMENDATIONS

The following recommendations start with the simplest implementations and progress to enhanced
performance utilizing additional components. Good performance is achieved even with the simplest
configurations. The implementations assume a low impedance balanced TX drive and a relatively high
impedance RX input, as is commonly available, though use with other TX/RX arrangements is
straightforward. Note that there are no changes to components on the line side, or in the hybrid, whether
600

Ω

or complex reference impedance selected, thus assisting country configuration. For complex

impedance, the matching circuits derived are suitable for reference impedances of the type 270 + 750//150nF
e.g. European CTR21 and 220 + 820//120nF (or 115nF) e.g. Australia, South Africa, etc., and yield similar
performance characteristics. For other impedances, please contact Profec Technologies.

Minimum Cost Implementations

Insertion Loss: 1.8dB @ 2kHz
Frequency Response : ±0.2dB 30Hz – 10kHz
Return Loss: 16dB 200Hz – 4kHz
Transhybrid Loss: 22dB 200Hz – 4kHz

Insertion Loss: 1.0dB @ 2kHz
Frequency Response : ±0.5dB 50Hz – 4kHz
Return Loss: 18dB 200Hz – 4kHz
Transhybrid Loss: 14dB 200Hz – 4kHz

Improved matching

Insertion Loss: 1.8dB @ 2kHz
Frequency Response : ±0.2dB 30Hz – 10kHz
Return Loss: 18dB 200Hz – 4kHz
Transhybrid Loss: 22dB 50Hz – 10kHz

Insertion Loss: 1.0dB @ 2kHz
Frequency Response : ±0.5dB 50Hz – 4kHz
Return Loss: 20dB 200Hz – 4kHz
Transhybrid Loss: 16dB 50Hz – 4kHz

600

Ω

Fig. 4

LINE

600

10nF

560

RXA

TXA2

TXA1

2 2 F

600

Ω

Fig. 2

LINE

600

560

RXA

TXA2

TXA1

2 2 F

10nF

LINE

270

(220)

750

(820)

2 2 F

150nF

(120nF)

750

100nF*

*Note: 100nF capacitor should have a temperature stable dielectric

120

European CTR21/(Australia, etc.)

Fig. 5

RXA

TXA2

TXA1

LINE

270

(220)

750

(820)

150nF

(120nF)

820

100nF*

*Note: 100nF capacitor should have a temperature stable dielectric

100

European CTR21/(Australia, etc.)

Fig. 3

RXA

TXA2

TXA1

2 2 F

Patented

P3356

ETALDOC 591/8

Page 4 of 5

January 2001

Improved matching and hybrid

Insertion Loss (Line to RXA): 2.8dB @ 2kHz
Frequency Response : ±0.2dB 30Hz – 10kHz
Return Loss: 20dB 200Hz – 4kHz
Transhybrid Loss: 30dB 50Hz – 10kHz

Insertion Loss (Line to RXA): 2.2dB @ 2kHz
Frequency Response : ±0.5dB 50Hz – 4kHz
Return Loss: 20dB 200Hz – 4kHz
Transhybrid Loss: 18dB 200Hz – 4kHz

600

Ω

Instrumentation

CERTIFICATION

Insertion Loss: 1.5dB @ 2kHz
Frequency Response : ±0.2dB 20Hz – 20kHz
Return Loss: 16dB 20Hz – 20kHz

SAFETY

Constructed in accordance with IEC 950:1991,
EN 60950:1992 (BS7002:1992) to amendment 5,
and UL1950 3rd Edition, supplementary insulation,
250Vrms maximum working voltage, flammability
class V-0.

There are no special installation requirements
(beyond attending to usual PCB track separations)
since the integral cover provides supplementary
insulation from its external faces to internal core
and windings.

Certified under the IEC CB scheme (Certificate
GB445W) to IEC 950:1991, up to amendment 4,
sub-clauses 1.5, 1.5.1, 1.5.3, 2.2, 2.2.3, 2.2.4, 2.9.2,
2.9.3, 2.9.4, 4.4, 4.4.3.2 (class V-0) and 5.3 for a
maximum working voltage of 250Vrms, nominal
mains supply voltage not exceeding 300Vrms
and a maximum operating temperature of 70ºC
in Pollution Degree 2 environments.

Recognized under the Component Recognition
Program of Underwriters Laboratories Inc. to US and
Canadian requirements CAN/CSA C22.2
No. 950-95/UL1950, Third Edition, including
revisions through to revision date March 1, 1998,
based on Fourth Amendment of IEC 950, Second
Edition, maximum working voltage 180Vrms
(creepage), 420V peak (clearance), Pollution
Degree 2, supplementary insulation.

UL File number E203175.
Approved and certified by BABT to EN 60950
and EN 41003.
BABT Certificate of Recognition 608755

Additionally, Profec Technologies certifies all
transformers as providing voltage isolation of
2.12kVrms, 3kV DC minimum. All shipments are
supported by a certificate of conformity to current
applicable safety standards.

600

Ω

Fig. 6

LINE

600

10nF

560

1nF

10k

RXA

TXA2

TXA1

2 2 F

10nF

1nF

LINE

270

(220)

750

(820)

2 2 F

150nF

(120nF)

750

100nF*

*Note: 100nF capacitor should have a temperature stable dielectric

120

European CTR21/(Australia, etc.)

Fig. 7

RXA

TXA2

TXA1

10k

47 F*

600

Ω

Fig. 8

600

Ω

600

Ω

6.8nF

* If no DC block required, one of these capacitors can be removed and

the other set to 22 F, or, if preferred, both capacitors can be eliminated.

Patented

P3356

ETALDOC 591/8

Page 5 of 5

January 2001

CONSTRUCTION

Dimensions shown are in millimetres (inches).
Geometric centres of outline and pin grid coincide within a tolerance circle of 0.6mmØ.
Windings may be used interchangeably as primary or secondary.
Total weight typically 6.3g.

ABSOLUTE MAXIMUM RATINGS

COPYRIGHT

(Ratings of components independent of circuit).

Short term isolation voltage (1s)

DC current
Storage temperature

Lead temperature, 10s

2.12kVrms,
3.0 kVDC
100

-40ºC to
+85ºC
260ºC

ETAL and P3356 are Trade Marks of Profec
Technologies Ltd.
The Trade Mark ETAL is registered at the UK
Trade Marks Registry.

Profec Technologies Ltd. is the owner of the
design right under the Copyright Designs and
Patents Act 1988 and no rights or licences are
hereby granted or implied to any third party.

P3356 design and construction are protected by
patents and registered design.
British Patent No. 2333646.
British Patent No. 2340667.
UK Registered Design No. 2077360.
French Registered Design No. 991512.
Germany Registered Design 49902311.0.
United States Registered Design 426, 815.
Other patents and registered designs pending.

T R A N S F O R M I N G T H E F U T U R E

Profec Technologies Ltd., 10 Betts Avenue, Martlesham Heath, Ipswich, IP5 3RH, England

Telephone: +44 (0) 1473 611422

Fax: +44 (0) 1473 611919

Websites: www.etal.ltd.uk

www.profec.com

Email:

info@etal.ltd.uk

sales@profec.com

Patented

Connections

ISO 9001

FM 25326

Dimensions